Funding is requested to support the purchase of a low temperature magic angle spinning (LT-MAS) probe that will be used with a 800/89 solid state spectrometer. The probe includes a cryogenic platform for cooling, transfer lines and the probe itself. The LT-MAS probe operates over the temperature range 90-300 K and will be used to examine a variety of temperature dependent phenomena in cryoprotected membrane protein and amyloid protein samples. The probe has a vacuum dewar, sample eject capabilities, and includes a waveguide for future low temperature dynamic nuclear polarization (DNP) experiments at 527 GHz. Research projects include the following membrane and amyloid proteins: (1) bacteriorhodopsin (bR), (2) the voltage dependent anion channel (VDAC) in lipid bilayers, (3) the M2 protein from influenza virus, (4) gas vesicles which form a proteinaceous membrane, and amyloid fibrils formed from (5) phosphatidyl inositol-3-kinase SH3 domain (PI3-SH3), (6) beta-2-microglobulin associated with dialysis related amyloidosis, and (7) the Sup35p protein, a yeast prion system. The LT-MAS probe on the 800/89 will be part of a cluster of instrumentation that serves a community of ~75 scientist performing high field biological NMR in the Boston area. The instrumentation will alleviate a pressing need for additional capabilities for low temperature MAS experiments. Further, the instrument will have a significant impact on research since it will employ a number of innovative technologies that are not generally available. In addition, the combination of the LT-MAS probe with the 800/89 will be one of the few widebore, low temperature solid state NMR instruments available in North America and will therefore fill an important void in structural biology.